Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds useful context beyond them: the output is an opaque payoff PNG with permanent source and risk warnings. This discloses an important output characteristic that the agent would not infer from annotations or schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, tight sentence with no filler. It front-loads the core action and then adds the essential output/warning behavior, which is appropriate for the tool's complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 10 parameters, a required symbol, and zero schema descriptions, the description is materially incomplete. It omits required inputs, source format expectations, the rights_confirmed gate, and the distinction between this and near-sibling strategy/plot tools.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate, but it only vaguely references a 'user-supplied chain' and does not explain key parameters such as symbol (required), strategy default, source_data, source_text, source_format, or rights_confirmed. The agent would struggle to know how to supply the chain or which parameters matter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action ('Build one option structure') and a concrete output ('opaque payoff PNG'), which separates it from generic plot or snapshot tools. It does not explicitly name sibling alternatives, so some ambiguity remains with option_strategy_plot, but the 'user-supplied chain' qualifier adds useful distinction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'from a user-supplied chain' implies this tool is for user-provided option data, but there is no explicit guidance on when to use this instead of option_strategy_plot, option_plots_from_snapshot, or other siblings. No exclusions or alternatives are named.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.